Single cartridge, self regulating, fuel efficient alcohol gel fireplace insert

ABSTRACT

A fireplace insert consisting of a noncombustible logset with a cavity that accepts a single, disposable, rectangular fuel cartridge containing alcohol gel fuel. The fuel cartridge sits below a vapor restrictor plate that restricts the amount of fuel that is fully exposed to ambient air but which also has one or more apertures. The plate and fuel cartridge, acting together, regulate the fire without any manually operated control knobs or adjustment mechanisms so as to produce a clean burning rectangular flame pattern that lasts at least one hour and flutters and peaks at predictable and acceptable heights, providing a visually pleasing fireplace effect without the use of any electric bulbs.

CROSS REFERENCE TO RELATED APPLICATIONS

Not Applicable

FEDERALLY SPONSORED RESEARCH

Not Applicable

SEQUENCE LISTING OR PROGRAM

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention is for a fireplace insert that efficiently burns alcohol gel in a single, disposable fuel cartridge, where the apparatus self regulates the shape, height, width, depth and burn time of the flames without manually operated control knobs or adjustment mechanisms, so as to produce a traditional, rectangularly shaped fireplace flame pattern that is visually pleasing and does not require supplemental illumination from electric bulbs.

2. Background

Traditionally, most fireplaces burned wood. Usually, the fires in those fireplaces had a rectangular flame pattern, i.e., a flame pattern that was wider than it was deep. This is because most fireplaces are wider than they are deep. Also, the logs placed inside fireplaces are usually wider than they are deep.

After wood burning fireplaces were developed gas fireplaces became popular. Gas fireplaces use what is commonly called an “insert” mechanism. A gas insert mechanism consists primarily of a set of noncombustible fake logs and a gas burner. Usually, the logs and gas burner are somewhat rectangular in that they are wider, left to right, than they are deep.

More recently, alcohol gel fireplaces have been developed. They use an insert consisting of noncombustible fake logs and an apparatus for burning alcohol gel fuel.

There are different types of alcohols and different methods of turning liquid alcohol, frequently diluted with water, into a gel. One example of an alcohol gel that can be used in an alcohol gel fireplace is described in U.S. Pat. No. 4,575,379 to Browning.

Depending on how they are combusted, some alcohols burn cleanly and do not require a chimney or exhaust system. If fake logs are placed directly over burning alcohol, however, it will not burn cleanly. Soot will develop.

Alcohol gel fireplace inserts do not produce as much heat as wood or gas fires, but they can produce a pleasing visual effect. To many consumers this is the key feature of a fireplace. Indeed, the visual effect is so important that many consumers use electric “fireplaces” that do not produce real fires, but create a pleasing visual effect with electric light bulbs and related mechanisms.

Fireplace inserts that burn alcohol gel fuel usually employ multiple round metal cans containing fuel. These cans are somewhat similar to large cans of “Sterno”. They appear to be, in essence, pint-sized paint cans. Currently they are sold under tradenames such as “Realflame” or “Sunjel”.

These “paint cans” are used by removing the lid and exposing the fuel. The alcohol in the fuel then vaporizes and mixes with ambient oxygen. If ignited the fuel will burn, producing a fire coming out of a can.

Fireplace insert mechanisms that use “multiple paint cans” present several problems, however.

First, many of these “multiple paint can” inserts require manually operated controls to regulate the shape, height, width, depth and burn time of the flames produced by the fuel burning in the cans.

Second, some of them require electric lights to supplement the illumination produced by the fuel burning in the cans.

Third, they use multiple cans of fuel as opposed to a single, disposable, fuel cartridge.

Fourth, some of them are relatively complex and have many components, especially when compared to the present invention, which has few components.

Fifth, because they use round cans they cannot produce a traditional rectangular flame pattern.

Sixth, “multiple paint can” systems that place noncombustible fake logs directly over the cans of burning fuel encourage the production of soot. Soot particles form under the fake logs and can also be carried into the room.

And seventh, it is inherently inefficient to use round cans of burning fuel to try to produce a rectangular fire. The round cans expose and burn more fuel than should be required to produce a rectangular fire. For example, if a 10″ wide rectangular flame pattern is desired, this result can be achieved by the current invention by exposing 10″×1″ of alcohol gel to ambient air. That exposes 10 square inches of alcohol gel fuel.

Round “paint cans”, however, expose and burn much more fuel in order to attempt to achieve a 10″ wide flame pattern. For example, using “paint cans” with 3.33″ round openings, placing three cans in a row will produce a flame pattern that is arguably 10″ wide. But, because the cans are round and each one exposes about 8.7 square inches of fuel, the total amount of fuel that is exposed is approximately 26.1 square inches. This is more than double the 10 square inches the current invention requires.

Hence, round “paint can” systems waste fuel. In this example they expose and burn over 260% more fuel than the current invention.

There is a need, therefore, for an alcohol gel fireplace insert that makes efficient use of fuel and solves the other problems discussed above. The current invention accomplishes this because:

-   -   (1) it self regulates the shape, height, width, depth and burn         time of the flames without manually operated control knobs or         adjustment mechanisms,     -   (2) it does not require an electric light or any other         supplement to the illumination provided by the burning alcohol         gel fuel,     -   (3) it uses a single disposable fuel cartridge, as opposed to         multiple cans of fuel,     -   (4) it has far fewer components than “multiple paint can”         fireplace inserts,     -   (5) it produces a rectangular flame pattern,     -   (6) it is fuel efficient because:         -   (a) it requires less fuel than a series of round cans to             produce a rectangular flame pattern, and         -   (b) it does not waste fuel by burning same to create flames             that are only partially visible to the consumer—all of the             fuel burned by the present invention creates flames that are             visible to the consumer,     -   (7) it does not produce soot particles by placing noncombustible         logs directly over the burning fuel.

DISADVANTAGES OF THE PRIOR ART

The prior art has not solved the problems listed above.

For example, U.S. Pat. No. 4,573,905, to Meyers, describes an alcohol gel fireplace insert that requires the use of multiple paint cans of fuel, Myers' component 194. Meyers uses three such cans, which he describes as “standard one-pint size” cans. Column 5, lines 14-18. Hence, Meyer's invention uses 48 ounces of fuel. This may be contrasted with the preferred embodiment of the present invention, which uses a 20 ounce fuel cartridge. That is a substantial fuel savings.

Also, Meyers requires a supplement to the illumination provided by burning the 48 ounces of fuel in his three cans. Myers' supplement is an electric “light fixture”. See Meyer's abstract and the body of his patent.

In contrast with Meyers, the present invention does not require any electric lights to supplement the illumination provided by the single, disposable, fuel cartridge.

Many of the problems in Myer's first patent are also present in Myers' next attempt, U.S. Pat. No. 4,890,600. This fireplace insert still uses multiple “cans of gel alcohol” instead of a single cartridge. (See Myers' abstract.) And, it still uses an electric light bulb (component 32) to supplement the illumination provided by burning the fuel in the cans.

Likewise, U.S. Pat. No. 4,838,781, to Fischer, has similar problems. Fisher's FIG. 2 shows four round cans of fuel. Assuming they are standard, one pint cans, that totals 64 ounces of fuel.

To repeat, the preferred embodiment of the present invention, however, uses a single 20 ounce fuel cartridge.

Moreover, Fisher's invention wastes additional fuel by hiding a part of the fire behind log 29 a in Fisher's FIG. 1. Hence, Fisher burns fuel that produces a fire that cannot be entirely seen. This is wasteful.

Moreover, Fisher's insert does not self regulate the shape, height, width, depth and burn time of the flames produced by the burning fuel. Instead, Fisher uses a manually adjustable “damper lid 22” which fits over the box, 12, containing his round fuel cans. See Column 5, lines 5-6.

Fisher's damper lid has to be manually pulled forward, using a “control tool”, to control the flame. As Fisher explains, “to control or dampen the flame coming from the ignited fuel containers 31, the control tool 28 is passed through an opening in the first simulated log 29, over the open fuel cell housing and the hook end 28 c is inserted into the control eyelet 25. Using tool 28 the lid is then pulled forward.” Column 6, lines 17-23.

Hence, Fisher and Myers do not disclose fireplace inserts that efficiently burn fuel in a single rectangular cartridge used in an apparatus that self regulates the shape, height, width, depth and burn time of the flames without manually operated control knobs or adjustment mechanisms.

Nor was this accomplished by Orlov, in U.S. Pat. No. 5,026,271. Orlov's fireplace insert has a drawer with a cover mechanism that requires manual adjustments to control the flame. Orlov uses a control rod, a control knob, a crossbar, an upstanding lug, an aperture plate, a drawer, a snuffer plate and other components to accomplish this. The control knob and rod have to be manually “pulled forwardly” to open or close the aperture over the burning fuel, thereby controlling the flame. As Orlov states:

-   -   “Extending forwardly from the center of the crossbar 46 there is         a control rod 54 having a front control knob 56, the rod 54         extending through an aperture in an upstanding lug 58 at the         front of the aperture plate 34, the rod also extending through a         vertical slot in the front wall 62 of the drawer 30. A circlip         64 is mounted in the groove in the control rod. Thus, when the         knob 56 is pulled forwardly, the snuffer plate 52 first moves         forward and progressively closes the aperture . . . ” Column 3,         lines 34-43     -   “(O)ne can then control the amount of flame emanating by moving         the knob forwardly so that the snuffer plate acts as a         regulating means and partially closes the aperture 36 to the         desired degree.” Column 4, lines 6-9.

Moreover, Orlov places fake, noncombustible logs directly over the burning fuel, as Orlov's FIG. 1 illustrates. When noncombustible logs are placed directly over burning fuel, however, soot forms on the underside of the logs and soot particles will rise into the air and room. This is not a clean way to burn fuel. Also, Orlov's insert wastes fuel by hiding a portion of the flames produced behind and underneath Orlov's noncombustible fake logs.

As previously described, it is inherently inefficient to burn a given quantity of fuel to produce a given quantity of flames, but then hide some of the flames behind or underneath fake logs.

Indeed, Orlov himself recognizes the importance of the visual effect. He states one object of his invention is to create a visual effect that is “pleasing . . . to the eye.,” Column 4, lines 4-5.

If that is the case, it is obviously inefficient to burn fuel which produces flames that the eye cannot see. It is more efficient to only burn fuel that produces flames the eye can see.

In contrast with Orlov, Bertolas, in U.S. Pat. No. 6,609,514, describes an invention that seems to visually expose all of the flames produced, but Bertolas does not disclose an insert which is placed inside a fireplace.

Instead, Bertolas discloses what he calls “a portable fire pit”. Moreover, Bertolas, similar to Fisher and Meyers, uses multiple “paint can type” cans of fuel, as opposed to a single, disposable, rectangular fuel cartridge. And lastly, Bertolas does not describe a mechanism that self regulates the shape, height, width, depth and burn time of the fire.

Similar to Bertolas, Hilker, in U.S. Pat. No. 4,076,490, discloses a fireplace insert that uses multiple round cans of fuel, versus a single, disposable, rectangular fuel cartridge. Nor does Hilker's invention produce a rectangular flame pattern. Instead, it produces three round fires coming from the three round cans of fuel, as FIGS. 1 and 2 in Hilker's patent clearly show.

Other patents disclose mechanisms for burning fuel, in general, but they are also different from the present invention. For example, Maust, et al., in U.S. Pat. No. 6,267,113 B1, does not disclose an insert which is placed inside a fireplace, but instead discloses a completely “free standing” fireplace hearth for use outdoors, on a “patio, deck, back yard or other similar outside settings.” Column 1, lines 9-10.

Moreover, Maust does not employ a single, disposable rectangular fuel cartridge, but instead requires “about 64 ounces” of fuel to be manually poured into the mechanism. See Column 9, lines 24-25.

And, Maust's invention does not self regulate the flame, but instead requires “manipulation” of a “knob” turning a “shaft” and moving “linkage” to regulate the flame. Column 9, lines 51-53. An invention that does not need these components, and can self regulate the shape and burn time of the flame, as the present invention does, is simpler.

Moreover, Maust places fake logs directly over the burning fuel. This produces soot. Maust claims “that sooting is kept to a minimum” in his invention (column 3, line 19), but he never defines that term.

In short, Maust does not reveal an indoor fireplace insert that burns alcohol gel in a single and disposable fuel cartridge efficiently, where the invention self regulates the width, height and depth of the fire without manually operated control knobs or adjustment mechanisms, so as to produce a rectangular flame pattern.

Nor do U.S. Pat. No. 3,993,430 to Forker, or U.S. Pat. No. 4,582,478 to Hilker, or 4,637,372, to Mogol. All of these reveal burner systems that employ liquid fuel, such as “fuel oil” (see Forker's Abstract), as opposed to alcohol gel fuel.

Liquid fuels, such as fuel oil, burn very differently from alcohol gel fuel. For one thing, when oils burn they produce noxious fumes. That is why oil burners have exhaust flues. Fireplace inserts that use liquid oils therefore require flues or chimneys, unlike the present fireplace insert.

Second, liquid oil flows. It can flow through pipes and tubes. See, for example, the pipe 22 in Hilker, and the tube 14 in Mogol.

Pipes and tubes will not work with alcohol gel, however, because it is thick. That is why it is called a “gel”. Gel will not flow freely through pipes and tubes.

Hence, the patents held by Forker, Hilker and Mogol do not disclose the present invention, which uses a single alcohol gel fuel cartridge and can be placed in a fireplace that does not have a chimney or exhaust flue.

In addition to this prior art, mention should also be made of the prior art regarding fuel cartridges.

Various types of fuel cartridges have been patented, but none of them are rectangular and burn alcohol gel in a fireplace mechanism that self-regulates the height, width, depth and burn time of the fire without adjustment mechanisms and only requires one cartridge to produce a rectangular flame.

For example, U.S. Pat. No. 5,584,283, to Messina, describes a round fuel cartridge similar to a “Sterno can” that shapes fire into a “toroidal” shape. Messina says this is better for cooking because a flame with “a substantially toroidal shape” creates higher temperatures. Column 1, lines 12-14.

Although Messina does discuss the importance of shaping the flame to suit a particular purpose, such as high temperature cooking, Messina does not disclose the present invention, nor does he disclose an alcohol gel fireplace insert apparatus that shapes a rectangular fire.

Aside from Messina, other patents discuss other fuel cartridges used for other purposes. For example, U.S. Pat. No. 5,062,222, to Billet, et al., describes a fuel cartridge used for heating a ski boot. U.S. Pat. No. 4,084,086, to Bandel, describes a fuel cartridge containing solid fuel and used to illuminate a lamp, and U.S. Pat. No. 4,896,653, to Eke, et al., describes another round, “Sterno-type” can used for cooking.

None of these fuel cartridge patents, however, disclose the present invention. None of them disclose an indoor fireplace insert that efficiently burns alcohol gel fuel in a single, disposable cartridge, where the apparatus self regulates the production of a traditional fireplace-type rectangular flame pattern, whose height, depth, width and burn time are self regulated without the need for manually operated control knobs or adjustment mechanisms.

Nor do these patents describe a disposable, generally rectangular, alcohol gel fuel cartridge, with a substantially open top, used singly in a fireplace insert mechanism that self regulates the height, depth, width and burn time of the fire without manually operated control knobs or adjustment mechanisms.

OBJECTS AND ADVANTAGES

The objects and advantages of the present invention are to provide an indoor fireplace insert mechanism that does not require an exhaust system and provides the pleasing visual effect of a traditional rectangular fireplace fire without using electric light bulbs, by cleanly and efficiently burning alcohol gel fuel in a single, disposable, rectangular fuel cartridge, where the invention self regulates the shape, height, width, depth and burn time of the flames without manually operated control knobs or adjustment mechanisms.

SUMMARY

In accordance with the present invention, there is provided an apparatus which includes a noncombustible fake logset with a cartridge-receiving cavity that communicates with the atmosphere and receives a single, substantially rectangular, disposable fuel cartridge containing alcohol gel fuel.

The fuel cartridge is made out of thin gauge metal and comprises a bottom, left sidewall, right sidewall, front wall and back wall, and a removable lid on top. When the lid is removed the cartridge has at least one substantially rectangular aperture which communicates with the atmosphere.

The noncombustible fake logset includes a substantially rectangular vapor restrictor plate that sits above the fuel cartridge and has at least one plate aperture. The vapor restrictor plate controls: (1) the flow of fuel vapor emanating from the fuel cartridge, and (2) the flow of ambient air toward the fuel in the cartridge.

The vapor restrictor plate and fuel cartridge, acting together, self-regulate the shape, height, width, depth and burn time of the flames produced when the fuel is ignited, without manually operated control knobs or adjustment mechanisms.

The disposable fuel cartridge may simply be dropped in the apparatus and ignited. The consumer may then enjoy the fire without manually adjusting any controls knobs or adjustment mechanisms.

The fire produced by the mechanism is visually appealing and does not require supplemental illumination from electric light bulbs. The invention is convenient and simple, insofar as it uses a single disposable cartridge, as opposed to multiple cans of fuel, or fuel that has to be measured and poured into a burner mechanism.

The invention is fuel efficient. It does not waste fuel by burning more than is necessary to achieve a traditional, visually appealing, rectangular flame pattern. In its preferred embodiment, it uses a 20 ounce fuel cartridge that will produce a fire lasting between one and a half to two hours.

The invention does not burn fuel that produces flames which the eye cannot see. All of the fuel burned produces flames that can be seen.

DRAWING—FIGURES

FIG. 1 shows one configuration of a rectangular metal fuel cartridge holding alcohol gel fuel, which cartridge fits into a cartridge-receiving cavity inside a set of noncombustible fake logs which may be unitary in structure but have the appearance of a series of log pieces. Above the cartridge-receiving cavity is a hinged vapor restrictor plate with two apertures.

FIG. 2 shows the rectangular metal fuel cartridge sitting in the cavity or holding area in the logset. The vapor restrictor plate is in the open position.

FIG. 3 shows the fuel cartridge in the cavity or holding area in the logset, with the hinged vapor restrictor plate is in the closed position.

FIG. 4 shows the fuel cartridge in the cavity with the vapor restrictor plate in the closed position, and shows Line 5 as a cross sectional reference point for use in FIGS. 5 and 6.

FIG. 5 is a cross-sectional view, taken along line 5 of FIG. 4, showing the relative positions of the vapor restrictor plate, the fuel cartridge, and the noncombustible log.

FIG. 6 shows a different embodiment of the logset 13 which has a metal liner in the cavity of the logset.

FIG. 7 shows one embodiment of a disposable rectangular fuel cartridge that holds about 20 ounces of fuel. Various portions have been labeled “A”, “B”, “C”, etc., to explain how the cartridge and vapor restrictor plate work together to regulate the fire without the need for manually operated control knobs or adjustment mechanisms. The explanation appears in the section herein entitled “Self Regulation of Fire.”

FIG. 8 shows one embodiment of a vapor restrictor plate for use with the disposable rectangular fuel cartridge shown in FIG. 7. Various portions have been labeled “D”, “E”, etc., to explain how the cartridge and vapor restrictor plate work together to regulate the fire without the need for manually operated control knobs or adjustment mechanisms. The explanation appears in the section herein entitled “Self Regulation of Fire.”

FIG. 9 shows an alternative embodiment of a vapor restrictor plate that may be used in tandem with the fuel cartridge illustrated in FIG. 7.

FIG. 10 shows another alternative embodiment of a vapor restrictor plate that may be used in tandem with the fuel cartridge illustrated in FIG. 7.

FIG. 11 illustrates a fire coming out of the vapor restrictor plate illustrated in FIG. 8.

DRAWINGS—REFERENCE NUMERALS

-   -   1 Invention     -   11 Disposable rectangular fuel cartridge     -   11A Cartridge aperture     -   12 Alcohol gel fuel in cartridge     -   13 Logset with cartridge-receiving cavity     -   14 Metal liner for logset cavity     -   15 Vapor restrictor plate     -   15A Alternative embodiment of vapor restrictor plate that will         function satisfactorily with rectangular fuel cartridge 11.     -   15B Alternative embodiment of vapor restrictor plate that will         function satisfactorily with rectangular fuel cartridge 11.     -   16 Vapor restrictor plate aperture     -   17 Hinge     -   19 Cartridge-receiving cavity     -   21 Fire

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT

The presently preferred embodiment of the invention is illustrated in FIGS. 1-11.

FIG. 1 shows a noncombustible fake logset 13 that gives the appearance of a series of logs, but which, in fact, may be cast as a unitary piece.

The logset 13 has a cartridge-receiving cavity 19 which communicates with the atmosphere and accepts the disposable rectangular fuel cartridge 11. The lid (not shown) of the disposable rectangular fuel cartridge 11 has been removed, so that the cartridge aperture 11A communicates with the atmosphere. The disposable rectangular fuel cartridge 11 contains alcohol gel fuel 12.

FIG. 2 illustrates the disposable rectangular fuel cartridge 11 sitting in the cartridge-receiving cavity 19 of the logset 13. Also shown is a hinged vapor restrictor plate 15 in the open, non-operating, position.

FIG. 3 illustrates the disposable rectangular fuel cartridge 11 sitting in the cartridge-receiving cavity 19 of the logset 13, with the vapor restrictor plate 15 in the closed, operating, position.

FIG. 4 is identical to FIG. 3 but also contains a cross-sectional viewpoint line, Line 5.

FIG. 5 shows the logset 13, cavity 19, disposable rectangular fuel cartridge 11, vapor restrictor plate 15 and the plate aperture 16.

FIG. 6 is identical to FIG. 5 but it also shows, as an alternative embodiment, a metal liner 14 sitting in the cartridge-receiving cavity 19 of the logset 13.

FIG. 7 shows one embodiment of a disposable rectangular fuel cartridge 11 that holds about 20 ounces of fuel. The lid on top of the cartridge has been removed and is not shown because there are numerous ways to construct a lid and no claim is being made for a novel way of constructing a lid. The cartridge aperture 11A permits communication between the fuel in the cartridge 11 and the atmosphere.

FIG. 8 shows one embodiment of a vapor restrictor plate 15 for use with the disposable rectangular fuel cartridge 11 shown in FIG. 7. This embodiment of a vapor restrictor plate 15 has two apertures 16.

FIG. 9 shows an alternative embodiment of a vapor restrictor plate 15A that may be used in tandem with the fuel cartridge 11 illustrated in FIG. 7.

FIG. 10 shows another alternative embodiment of a vapor restrictor plate 15B that may be used in tandem with the fuel cartridge 11 shown in FIG. 7.

FIG. 11 shows a fire 21 emanating from the vapor restrictor plate apertures 16 in vapor restrictor plate 15.

Operation

The consumer removes the lid covering the top of the disposable rectangular fuel cartridge 11. The lid is not shown because it can be constructed numerous ways and no claim is made regarding a novel lid.

After the lid has been removed the consumer places the disposable rectangular fuel cartridge 11 in the cartridge-receiving cavity 19 of the logset 13 and positions the vapor restrictor plate 15 directly over the fuel cartridge 11. The alcohol gel 12 is then ignited.

A fire 21 results that will flutter and peak at predictable heights, at a set depth, and in a rectangular flame pattern, for the duration of the burn cycle. There are no manual control knobs or mechanisms that need to be adjusted or operated. The invention self regulates the fire, as described subsequently.

Self Regulation of Fire

Whereas other alcohol gel fireplace inserts use manually operated control knobs or adjustment mechanisms to regulate the fire, this invention self regulates the shape, height, width, depth and burn time of the fire by the combined operation of the disposable rectangular fuel cartridge 11 and the vapor restrictor plate 15, and more particularly, the measurements of each.

As an example, the measurements of a preferred embodiment of a disposable rectangular fuel cartridge 11 and a vapor restrictor plate 15 are labeled “A-P” in FIGS. 7 and 8.

As FIG. 7 shows, “A” represents the interior width of the top opening of disposable fuel cartridge 11. “B” represents the interior depth of the opening of the cartridge 11. “C” represents the interior height of the cartridge 11.

For illustrative purposes the cartridge 11 in FIG. 7 is shown as a perfect rectangle. The cartridge 11 may also be substantially rectangular, however. For example, the sidewalls of the cartridge 11 may be tapered inwards, as shown in FIGS. 5 and 6. Also, the corners of the generally rectangular cartridge may be slightly rounded.

On the embodiment of the vapor restrictor plate 15 shown in FIG. 8, “D” represents its width and “E” represents its depth. “F”-“P” represent the measurements of the portions of the vapor restrictor plate 15 which surround the two vapor restrictor plate apertures 16 in this embodiment, and the measurements of the apertures 16 themselves.

The relationship of measurements “A-P” on the cartridge 11 and restrictor plate 15 will control the shape, height, width, depth and burn time of the fire produced when a given type of alcohol gel fuel 12 is ignited.

Using, for example a mixture that is approximately 70% isopropyl alcohol and 30% water, plus thickening agents to achieve a viscosity of about 70,000 centipoise, the table below describes one type of desirable fire. Self Regulating Rectangular Fire: Example 1 Burn Time: Approximately 1.5-2 hours. Width of Fire: Approximately 9″ Depth of Fire: Approximately 1″ Height of Fire: Flutters between 4″-6″, approximately. Peaks at 8″-10″, occasionally 12″.

To achieve this fire the approximate measurements in the disposable fuel cartridge 11, containing about 20 ounces of gel, are: A = 10″ B = 2″ C = 2″

The approximate measurements of the vapor restrictor plate 15 which may be used with this cartridge 11 are: D = 10.2″ E = 2.2″ F = .6″ G = .6″ H = .6″ I = .6″ J = .6″ K = 1″ L = 4.2″ M = 1″ N = 4.2″ O = .6″ P = .6″ This combination will produce a fire that flutters 4″-6″ above the vapor restrictor plate 15, and will peak at 8-10″, occasionally 12″. Such a fire is suitable for typical alcohol gel fireplaces sold today that can accept an 18″ wide logset 13 in a firebox that is approximately 23″ wide and about 20″ high.

The invention will self regulate the fire because of the following: Measurements A and B of the fuel cartridge 11 are 10″ and 2″, respectively. Hence, twenty square inches of surface area of alcohol gel fuel 12 exist at the top of the cartridge 11. Dimensions D and E of vapor restrictor plate 15 however, are larger than measurements A and B of the cartridge 11. Hence vapor restrictor plate 15, when used with fuel cartridge 11, partially covers the cartridge 11 and restricts both: (1) the flow of ambient oxygen towards the alcohol gel fuel 12, and (2) the flow of evaporated fuel out of the cartridge 11.

Because vapor restrictor plate 15 has two apertures 16 that each measure 1″ by 4.2″, it only fully exposes 8.4 square inches of alcohol gel fuel 12 to ambient air.

When vapor restrictor plate 15 is used in conjunction with fuel cartridge 11, it is the shape of these 8.4 square inches, as illustrated in FIG. 8, that produces the rectangular flame pattern with the time duration and size characteristics cited earlier.

In this regard the shape of the 8.4 square inches should be distinguished from the total of 8.4 square inches. All shapes which fully expose 8.4 square inches of fuel to ambient air will not operate the same way.

For example, 8.4 square inches of fuel exposed by a vapor restrictor plate with a large, centrally located 2″×4.2″ opening will only produce a fire about 4.2″ wide. This is not acceptable in a fireplace that has a 23″ wide firebox. Also, the burn time of that fire, and its height and depth, will not be the same as that produced by the vapor restrictor plate 15 illustrated in FIG. 8.

Moreover, if a vapor restrictor plate with a centrally located 2″×4.2″ opening is placed over the fuel cartridge 11 illustrated in FIG. 7, it may not allow substantially all of the fuel 12 in the cartridge 11 to burn.

This is because the fuel 12 in the extreme left and right bottom corners of the cartridge 11 may be too far away from the aperture to allow enough ambient air to reach the fuel in a room with static air, as opposed to a room with several large, actively turning, ceiling fans.

In sum, then, a vapor restrictor plate used in tandem with a single disposable rectangular fuel cartridge must: (1) allow substantially all the fuel to burn, (2) burn fuel efficiently, (3) produce a wide flame pattern, (4) produce flames that flutter and peak at acceptable minimum heights, (5) avoid excessive flame heights, (6) produce a flame duration that is at least one hour, and (7) accomplish this without any manually operated control knobs or adjustment mechanisms.

FIGS. 7 and 8 show a tandem vapor restrictor plate 15 and fuel cartridge 11 that accomplishes this result with extreme fuel efficiency. It only uses 20 ounces of fuel, compared with the 48 ounces used in Myers' U.S. Pat. No. 4,573,905, or the 64 ounces used by Maust and Fisher.

Moreover, this vapor restrictor plate 15 and fuel cartridge 11 actually produces a 9″×1″ flame pattern while only exposing 8.4 square inches of fuel. They do this because flames overlap and cover the central portion of the vapor restrictor plate 15, as illustrated in FIG. 11. Hence, a 9″×1″ fire is produced while only burning fuel exposed in an 8.4 square inch area.

The scope of the current invention, therefore, should be determined by the concepts explained above and the appended claims, and their legal equivalents, rather than by the specific descriptions illustrated in the figures.

Alternative Embodiments

One alternative embodiment, shown in FIG. 6, employs a metal liner 14 in the cartridge-receiving cavity 19 of the logset 13. Another alternative embodiment omits the hinges 17, and simply rests the vapor restrictor plate 15 on top of the fuel cartridge 11.

Other alternative embodiments are possible by altering measurements on the fuel cartridge 11, the vapor restrictor plate 15, and/or the vapor restrictor plate aperture(s) 16, to produce fires with different qualitites.

For example, using the same fuel cartridge 11 shown in FIG. 7, holding about 20 ounces of fuel, with the same double aperture 16 type of design on the vapor restrictor plate 15 shown in FIG. 8, if the size of the apertures 16 is increased slightly the fire 21 will be larger but will burn for a shorter period of time. If the size of the apertures 16 is decreased slightly the fire 21 will be smaller but will burn longer.

Burn time can also be altered without affecting the size or shape of the fire 21. This can be done by altering the height of a given fuel cartridge so that it holds more or less fuel. For example, increasing the height of the cartridge 11 shown in FIG. 7 from 2″ to 2.5″ so that its capacity increases from about 20 ounces to about 25 will increase the burn time of the cartridge.

Other variations in measurements can be easily imagined and are too numerous to list. Recall, however, that it is the relationship of the measurements on a fuel cartridge and vapor restrictor plate which control the shape, height, width, depth and burn time of the fire produced. These relationships may be varied to produce “Cartridge and Restrictor Plate Sets” that produce a wide variety of fires. 

1. A fireplace insert comprising: a noncombustible logset having a cartridge-receiving cavity which communicates with the atmosphere, a fuel cartridge having at least one cartridge aperture, located within said cartridge-receiving cavity, and a vapor restrictor plate having at least one plate aperture, said vapor restrictor plate being disposed proximate to said rectangular fuel cartridge so that said cartridge aperture is proximate to said plate aperture and said fuel cartridge communicates with the atmosphere.
 2. The fireplace insert of claim 1, wherein said cartridge-receiving cavity is substantially rectangular.
 3. The fireplace insert of claim 1, wherein said vapor restrictor plate is substantially rectangular.
 4. The fireplace insert of claim 2, wherein said vapor restrictor plate is substantially rectangular.
 5. The fireplace insert of claim 1, wherein said cartridge aperture is substantially rectangular.
 6. The fireplace insert of claim 1, wherein said plate aperture is substantially rectangular.
 7. The fireplace insert of claim 5, wherein said plate aperture is substantially rectangular.
 8. The fireplace insert of claim 1, wherein said cartridge-receiving cavity is substantially rectangular, said vapor restrictor plate is substantially rectangular, said cartridge aperture is substantially rectangular, and said plate aperture is substantially rectangular.
 9. The fireplace insert of claim 1, wherein said fuel cartridge comprises alcohol gel fuel.
 10. The fireplace insert of claim 9, wherein said fuel cartridge comprises alcohol gel fuel.
 11. A substantially rectangular alcohol gel fuel cartridge comprising: a bottom, a left sidewall, a right sidewall, a front wall, a back wall, a substantially open top, said fuel cartridge containing alcohol gel fuel.
 12. A substantially rectangular alcohol gel fireplace insert fuel cartridge comprising: a bottom, a left sidewall, a right sidewall, a front wall, a back wall, a substantially open top, said fuel cartridge containing alcohol gel fuel. 